How to limit: manual, programmatic input and any occurrence of a specific double number in textBox.text?

Question

C++ / C#

How is it possible to implement a limitation: manual or programmatic input, as well as any possible manifestation of a certain double number (0.59 and below it) in textBox.text?
That is, you need to prohibit it altogether, so that, according to the idea, it was about to appear, but the ban worked and this number did not appear, but another appeared that, say, is closer to it (that is, I need to prohibit absolutely any occurrence of double number 0, 59 and below it, and if it is about to appear, a double number 0.60 has appeared instead)